Search or add a thesis

Advanced Search (Beta)
Home > Weed Management Studies in System of Rice Intensification Sri .

Weed Management Studies in System of Rice Intensification Sri .

Thesis Info

Access Option

External Link

Author

Chadhar, Asim Raza

Program

PhD

Institute

University of Agriculture

City

Faisalabad

Province

Punjab

Country

Pakistan

Thesis Completing Year

2014

Thesis Completion Status

Completed

Subject

Applied Sciences

Language

English

Link

http://prr.hec.gov.pk/jspui/bitstream/123456789/2560/1/2865S.pdf

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676727671655

Asian Research Index Whatsapp Chanel
Asian Research Index Whatsapp Chanel

Join our Whatsapp Channel to get regular updates.

Similar


Rice is an important crop of Pakistan. Weed infestation and traditional rice growing methods are resulting in low rice yield. System of rice intensification (SRI) has emerged as an alternative and resource efficient rice production method. Field experiments were conducted, for two consecutive years (2010 and 2011), to assess the outcome of different weed management practices and to determine critical weed competition period in rice (Oryza sativa L.) under the system of rice intensification. Experimental site was Agronomic research Area, University of Agriculture, Faisalabad, Pakistan. First experiment comprised the application of different weed control practices in SRI i.e. three times manual hoeing, three times hoeing with rotary hoe, one manual hoeing followed by foliar application of crop-water extracts, one hoeing with rotary hoe followed by crop-water extracts, post emergence application of orthosulfamuron @ 145 g a.i. ha-1, weed free and a control. Seedlings of 21 days age were transplanted in this experiment. Manual hoeing 20, 40 and 60 days after transplanting (DAT) with 5.34 and 4.99 t ha-1 kernel yield during 2010 and 2011, respectively, was recorded the best weed management method in SRI. Second experiment comprised plant spacing of 20, 25 and 30 cm and competition periods of 20, 40, 60, and 80 days after transplanting along with control and weed free treatments. In this experiment 21 days old seedlings were transplanted. The third experiment consisted of transplanting seedlings of 14, 21 and 28 days and competition periods of 20, 40, 60, and 80 days after sowing along with control and weed free treatments. The weed competition periods were randomized in sub-plots while plant spacing and seedling age were randomized in main plots in second and third experiment, respectively. All the experiments were replicated thrice. Super basmati variety was used. Nursery was raised on a soil enriched with farm yard manure and the seeds, after sowing, were covered with straw to preserve moisture and prevent the germinating seeds from heat injury and predators. One seedling per hill was transplanted in a muddy soil, and irrigation was provided in intermittent intervals as per requirements of SRI. Data pertaining to various parameters related to rice crop and weed species was recorded using the standard procedures and was analyzed using Fisher’s analysis of variance technique. Least significant difference (LSD) test at 0.05 probability was used to compare the significant treatments’ means. From the first experiment, manual hoeing 20, 40 and 60 days after transplanting (DAT) with 5.34 and 4.99 t ha-1 kernel yield during 2010 and 2011, respectively, was recorded the best weed management method in SRI. Second experiment showed that the combination of 25 × 25 cm spacing and competition for 20 DAT with kernel yield 5.4 and 5.3 t ha-1 during 2010 and 2011, respectively, was the most economical treatment combination. Moreover, experiment three ended with the finding that the combination of 21 days old seedlings and competition for 20 DAT was the most economical treatment combination in terms of kernel yield of rice i.e. 4.9 and 4.7 t ha-1 during 2010 and 2011, respectively. In short, Pakistani farmers can confidently adopt SRI to maximize their rice yield and to minimize their inputs. Minimal dependence of SRI upon synthetic chemicals can ensure environmental safety on sustainable basis.
Loading...
Loading...

Similar Books

Loading...

Similar Chapters

Loading...

Similar News

Loading...

Similar Articles

Loading...

Similar Article Headings

Loading...

غزلیات

ستم یہ مجھ پہ زمانے نے بار بار کیا
اسی نے لوٹ لیا جس پہ اعتبار کیا

تمام عمر نبھانے کا توڑ کر پیماں
لباسِ ہستی مرا اس نے تار تار کیا

جو آنے والا نہ آیا تو یوں ہوا تائبؔ
تمام عمر اسی کا ہی انتظار کیا

سیکولرازم اور مسلم معاشرے میں اس کا ارتقاء: تحقیقی مطالعہ

The concept of Secularism came to the Muslim world after Renaissance. Historically, the initial thoughts on the subject are found in the teachings of Greek Philosophers like Epicurus and Zeno. It was at first a discussion regarding the separation of religion and the state, the scientific advancements and the regime system in Modern Europe. Religion was considered as an obstacle by the West in their progress on the basis of reason and inquiry. Adaptation of secular approach helped the western countries to flourish in material fields. In Islamic world, secularism was not seen as a threat for religion before the twentieth century. Under colonization of many Muslim countries and particularly after the demise of Ottoman Empire which paved way to abolish Caliphate, the Muslim states adopted various western secular laws. Moreover, the Muslim countries went under heavy debts taken from European countries. They relied on foreign advisors and western education system for progress. The concept regarding the authority of Caliph changed. During the twentieth century, Muslim countries suffered politically and their geographical frontiers were changed. It created a kind of revolution in Muslim states. Revival of religious authority in modern political Muslim states is visible in central eastern countries during the last fifty years.

Improvement of Potato Solanum Tuberosum L. for Abiotic Stress Tolerance Through Genetic Engineering

Input applications of agricultural and industrial activities have increased salt levels in our soils. In the modern era of agricultural production of crops, shortage of water resources makes them inaccessible for growing crops. Plant species have different mechanisms that deal with the salt tolerance; but the capability to sustain low cytosolic Na+ is supposed to be one of the vital factors of plant salt tolerance. Removal of Na+ from the cytoplasm of the cells and/or the maintenance of the low cytosolic Na+ concentrations is carried out either by pumping Na+ out of cells (plasma membrane antiporter) or into the vacuoles (vacuolar antiporter) under high salinity conditions. This process is brought about by the operation of plasma membrane-bound H+-pumps responsible for energizing Na+/H+ antiporters. In addition to this, engineering of the regulatory machinery involving transcription factors has emerged as a new tool now for controlling the expression of many stress-responsive genes. Development and use of transgenic plants with enhanced capability of salt tolerance by over-expression of genes may help to meet the future challenges of abiotic stresses. The effect of plant growth regulators in different combinations on in vitro regeneration of currently grown potato cultivars (cvs). ‘Kuroda’, ‘Cardinal’ and ‘Desiree’ were determined. Overall, the callus production and in vitro regeneration efficiency was maximum in Cardinal and Kuroda. Media combination and cultivars having potential for good callus induction and regeneration were selected for transformation. The novel synthetic HSR1 gene was cloned under double CaMV35S promoter in the pGreen0029 plant expression vector. HSR1 and AVP1 genes were transformed in potato through Agrobacterium-mediated transformation method. Putative transgenic calli and regenerated shoots were obtained in the presence of kanamycin (50 mg/ml) as plant tissue selection agent. Varying transformation efficiencies (30 and 25 %) were observed in different batches for Kuroda and Cardinal, respectively. A total of 57 transgenic plants were obtained from independent events and were successfully established in pots containing sterilized sand. Transgenic plants were confirmed by PCR and Southern hybridization. Variable numbers (1-4) of integration sites for the transgenes were observed in the genomic DNA of transgenic potato plants when AVP1/HSR1 specific probes were used for Southern analysis. In order to check abiotic stress tolerance potential, transgenic plants were subjected to in vitro screening in response to different levels of stress inducing agents like NaCl and PEG (6000). Agronomic parameters (shoot length, root length, leaf area index, shoot fresh weight, shoot dry weight, root fresh weight, root dry weight and relative water contents) were recorded that shows the transgenic potato lines performed better under stress conditions compared to the control plants. Transgenic potato plants containing AVP1 and synthetic HSR1 genes were analyzed for salt stress tolerance. Significantly (P ≤ 0.05) higher photosynthetic rates, stomatal, sub-stomatal conductance and transpiration rate were observed in transgenic plants harboring HSR1 and AVP1 genes compared to control plants. Higher Membrane Stability Index was noted in transgenic plants than non-transformed plants. Transgenic plants showed higher accumulation of Na+, K+ and a higher Na+/K+ ratio than non-transformed plants. Salt analyses showed high accumulation of total free amino acids, proline contents, and total soluble sugars indicating salt tolerance manifested by transgenic AVP1 and HSR1 plants. To avoid the toxic level of ROS and protect the cells from oxidative injury, accumulation of complex antioxidant enzymes such as superoxide dismutase (SOD) (EC 1.15.1.1), peroxidase (POD) (EC 1.11.1.7), ascorbic peroxidase (APX) (EC 1.11.1.11) and catalase (CAT) (EC 1.11.1.6) were determined in stressed leaves which showed a significantly higher accumulation in transgenic potato plants compared to controls. Tunnel experiment was performed for yield components to check the potential of transgenic plants under various levels (100, 75 and 50%) of drought stress. Significantly (P ≤ 0.05) higher biomass, number of tubers/plant and weight of tubers/plant was observed at 75 and 50% of drought stress. This study provides an efficient protocol for regeneration efficiency of potato cultivar Kuroda, Cardinal and Desiree using internodal explants. The results suggest that transgenic plants expressing higher levels of AVP1 and HSR1 transcripts in potato are able to withstand salt and drought stress regimes.